smith



Sept. 24, 1963 H. A. SMITH, JR

HAMMERS 3 Sheets-Sheet 1 Filed Sept. 18, 1961 .11 wmww 1.. 2 mm o 2% MAX mi a P 1963 H. A. SMITH, JR 3,104,838

HAMMERS Filed Sept. 18, 1961 '5 Sheets-Sheet 2 Fig.3

' ZLA-22-B F19 W1 Mp M I I W 1 I" M HI Inventor ng A.6mith,Jr.

mofneuts P 1963 H. A. SMITH, JR 3,104,838

HAMMERS Filed Sept. 18, 1961 3 Sheets-Sheet 3 I .ll II Inventor fiarrg flnSmi Hz, Jr.

United States Patent 3,104,838 HAMIVIERE? Harry A. Smith, .112, Crete, IlL, assignor to American Brake Shoe Company, New York, N.Y., a corporation of Delaware Filed ept. 18, 1961, ger. No. 138,772- 7 Claims. (Q5. 241-197) This invention relates to a hammer of the kind used in a hammer mill where the hammer rotates in a relatively confined area.

The conventional hammer mill construction is one wherein the hammer is carried for rotation on a shaft, and when the mill is in operation the hammer is rotated in the mill chamber to repeatedly impact the charge fed to the mill. The head of the hammer represents the working part and its subjected to a great deal of wear, and it has heretofore been proposed to separably relate the head and the shank to enable the head to be replaced when unduly worn.

Replacement of the hammer head is a particularly tedious operation, and in fact it is necessary to at least partly disassemble the mill in some instances in order to replace the hammer head. This is particularly so under circumstances where the mill chamber is of relatively narrow construction, and the primary object of the present invention is to enable the head of a hammer of the kind involved to be easily replaced without removing the side plates from the mill or without removing the shank of the hammer from the mill shaft.

Specifically, the object of the present invention is to construct a hammer for a hammer mill to include a twopiece shank having projections thereon adapted to interfit with complemental surfaces on the hammer head within a recess of the hammer head. The inter-fitting relationship is maintained by at least one separate spacer plate so constructed as to normally have .a portion thereof disposed in the aforesaid recess, filling the recess and preventing endwise separation of the interfitting parts. The spacer element is held in its effective position by releasable securing means, but upon release or removal of the securing means the spacer element is free to be removed to an inffective position whereat endwise displacement of the inter-fitting parts is possible with consequent separation of the hammer members.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which, by way of illustration, show preferred embodiments of the present invention and the principles thereof and what are now considered to be the best mode for applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims.

In the drawings:

FIG. 1 is a side elevation of one form of hammer constructed under the present invention;

FIG. 2 is a sectional view taken substantially on line 22 of FIG. 1;

FIG. 3 is a sectional view of the hammer head used with the construction illustrated in FIG. 1;

FIG. 4 is a side elevation of the spacer plate used with the hammer construction illustrated in H6. 1;

FIG. 5 is a side elevation of one of the identical shank pieces used in the hammer construction illustrated in FIG. 1;

FIG. 6 is a side elevation, showing the hammer head partly broken away, of another form of hammer construction under the present invention;

djd ifid Patented Sept. 24, 1963 FIG. 7 is a sectional view taken substantially on the line 77 of FIG. 6;

FIG. 8 is a side elevation of one of the shank pieces used in the hammer construction illustrated in FIG. 6;

FIG. 9 is a sectional View taken substantially on the line 9-9 of FIG. 8; and

FIG. 10 is a side elevation of one of the two identical spacer plates used for the hammer construction illustrated in FIG. 6.

The separable hammer of the present invention is one specifically constructed for use in a hammer mill, and in particular in a hammer mill where relatively little working space is available for repair or replacement of the hammer head of the separable hammer used in such a mill. Thus, the hammer in the present instance is of the separable type, that is, the head is removably joined to the hammer shank, and the construction is of such nature.

that very little manipulation of parts is required incidental to removal of the head from the shank. In fact, in making a separation under the present invention, it is merely necessary to have the hammer assembly disposed within the mill in a position where the head can be reached, and then to release the securing means hereinafter identified, whereafter the spacer is move-d to an ineffective position making it possible to disengage the interfitting parts by in effect moving the shank endwise on the hammer mill shaft.

One form of the present invention is illustrated as embodied in the hammer assembly 20*, FIG. 1, that is inclusive of a heavy, sturdy head member '21 and a twopiece shank member 22. The shank member 22 comprises a pair of identical shank elements 22A and 22B.

The hammer head is rectangular in cross section as will be noted in FIG. 2, having flat outer sides 24- and 25, an arcuate lower face 26, flat end faces 27 and 28 and a flat top wall 30 which is recessed as will hereinafter be de scribed in detail.

The shank member 22 is arranged to dependingly relate the hammer assembly as a whole to the main shaft MS in the mill. To this end, the identical elements 22A and 22B that comprise the shank assembly are formed with circular openings 31 adjacent what amounts to the upper end of the shank, and since the shank elements are of identical construction the related reference characters in the description to follow apply to both shank elements 22A and 2213. Thus, each shank element intermediate the ends thereof, on each side, is formed with lugs 33 and 34-, FIG. 5, which, as shown in FIG. 1, have flat lower faces opposite the top wall 30 of the head.

The end of each shank element opposite the opening 31 therein is shaped to have an outwardly directed p-ro jection or claw 36 thereon. Each such projection, as shown in FIG. 5, is convex or humped in nature, and specifically is triangular in shape so as to have a pair of sloped faces 37 and 38 which slope downwardly from an apex 49 that is disposed to point in the direction of the shank opening 31.

As noted above, the head of the hammer is recessed downwardly from the top wall 30, and this recess is identified by reference character 41. It will be noted that the recess 41 is relatively deep in character, quite wide and is in part bounded by relatively narrow overhanging projections or ledges 42 and 43 at the top thereof on opposite sides of the recess 41.

The projections 42 and 43 have lower concave surfaces as 42A and 43A shaped complemental to the projection or claw 36 on the related shank element. Thus, when the shank elements are related as they are shown in FIG. 2, with the lower head-holding end thereof disposed in the hammer head recess 41, the projection 36 on each shank element faces outwardly so as to underlie and complementally interfit with the overhanging projection as 42 (or 43 as the case may be) within the recess in the hammer head. Thus, the claw on the shank element is interfitted with the claw on the hammer head, and when the two shank elements are related in this manner to the hammer head, the latter is supported in a uniform or symmetrical fashion. This relationship is secured and maintained by spacer means as will now be described.

Under and in accordance with the present invention, endwise displacement of the interfitted parts within the hammer head recess as 41 is prevented by spacer means disposed in an effective position within the recess to maintain the interfitting en agement, and in the form of the invention illustrated in FIGS. 1 to 5 the spacer means is in the form of a single spacer plate 4-5 interposed between the shank elements 22A and 22') in their operative position.

Referring to FIG. 2, it will berecognized that the combined width of the ends of the shank and spacer'elements in the recess 41 is such as to fill the recess ll, considered from the standpoint of width immediately beneath the overhanging projections 42 and when the claws 36 of the shank elements are interfittingly related to the overhanging projections in the hammer head recess, there is a resultant space between the opposed faces of the shanks 22A and 22B, and this space is normally filled by the lower end of the spacer plate 25 to prevent endwise displacement of the interfittted shank and hammer parts within the recess 41.

As noted above, the shank elements have apertures adapted to embrace the shaft of the mill. As shown particularly in FIG. 4, the spacer plate 45 is slotted down- Wm'dly from the upper end at 45A, and this U-shaped slot terminates about midway of the length of the space plate. The slot 55A is of sunicient width to embrace the hammer mill shaft, and it will be realized from a comparison of the diameter of the openings 31 and the length of the slot 45A that the spacer plate 45 is free for considerable radial displacement, that is, displacement parallel to the axes of the shank elements 22A and 228 when aligned therewith. Such radial displacement is, however, normally prevented by securing means, and such securing means is in the form of a nut and bolt assembly YB, PlG. 1, observing that each shank element is formed with an aperture 4-7, PEG. 5, and the spacer is formed with a related aperture to be registered therewith to enable the shank of the bolt B to be passed therethrough as will be evident in PEG. 2.

The nut N, FIG. 2, when tightened holds the shank pieces tightly together, and at the same time, it may be noted, the spacer plate 4-5 is positively held thereto for rotation with the shank. Advantageously, additional apertures 54) and 51 are provided in the spacer plate and in the shank pieces as shown in FIGS. 4 and 5, and these will be aligned when the parts are. assembled as shown in FIG. 2. The resultant passageway enables a cotter, wire or the like to be disposed therein and bent or otherwise deformed to embrace the nut and prevent inadvertent loosening thereof durini use of the hammer.

The outer face of the shank members, where the nut and the head of the bolt are located, are reecssed at RC to afford protective seats for the nut and the head of the bolt.

Additionally, the hammer head is provided with strategically located passageways as 55am] S6 which extend from the outer surfaces thereof to the recess 41, and these enable a cleaning tool to be inserted therein to clear the recess 41 in the event that this should become necessary, particularly to facilitate disassembling the hammer head.

The operative assembly is illustrated in FlGS. 1 and 2, and in order to remove the head of the hammer it is merely necessary to remove the nut and bolt assembly NB and thereafter slide the spacer plate 45 radially upwardly on the shaft MS (as viewed in FIG. 2) to displace the lower end thereof from the recess 41. The spacer plate can then be slipped from the mill shaft, making possible endwise separation of the engaged projections Within the recess 41. As a consequence, the head of the hammer can he slipped from the shank once the projections 36 of the latter are free of the overhanging projections 52 and 43 within the hammer head recess 41. It will be realized from this that separation of the hammer head can be effected without dismantling the mill so long as the having the head to be replaced is moved to an accessible position, say adjacent the charg ing door of the mill.

Another form of the present invention is illustrated in FIGS. 6 to 10, and referring thereto it will be noted that the hammer assembly on the basis of outward appearances, is virtually identical to the hammer assembly described above. Again, the shank assembly 61 includes a pair of identical shank pieces or elements 61A and till-3 having enlarged apertures 63, FIG. 8, enabling the shank to be hung on the mill shaft MS.

in the form of the invention illustrated in FIGS. 6 to 10, the projections at the l wer end of the shank to be interfitted with related parts on the hammer head are in the form of claws 65 which normally extend toward one another, rather than facing in opposite directions in the manner of the projections above described. Again,

however, the interitting relationship occurs within the recess 6? in the hammer head 7%, and the side wall portions of the hammer head are provided with apertures 72 and 73 which extend into the recess 69 to enable the interior of the rcess 69 to be cleaned by a suitable tool extended thereinto.

The projections 65 have arcuate concave upper faces as will be evident in FIGS. 8 and 9 and these curved faces re adapted to engage a corresponding pair of convex downwardly facing surfaces presented by the convex underside margins of a transverse strap or bar 75 castintegral with the head 7b, as shown in FIGS. 6 and 7, and located medially of the recess 69 to be within the recess as in the foregoing embodiment.

The shank elements 61A and 61B are to be disposed, in their operative position, in back-to-back relationship as shown in FIG. 7 with the inwardly directed projections 65 thereon embracing the strap 75. Thereafter, spacer means in the form of a pair of identical spacer plates and 83. are juxtaposed on the outer sides of shank pieces, with the lower ends thereof disposed within the outer limits of the hammer head recess 69. Each spacer plate, as shown in FIG. 10, is formed with an elongated U- shaped slot adapted to embrace the mill shaft MS, and it may be noted that the side plates of the mill confine and prevent endwise displacement of the spacer plates 80 and 81 relative to the shaft MS.

The combined width of the spacer plates 80 and 81 and l and it will be observed from FIG. 7 that the ends of the,

spacers extend into the recess 69 sufiiciently far (beyond the nut and the head of the bolt) as to be incapable of clearing the same when moved in the direction ofthe main shaft, unless the nut and bolt are removed.

The operative arrangement of parts is illustrated in FIGS. 6 and 7, and in the event that it should become 1 necessary to remove or reverse the hammer head 70, the first and preliminary step is to remove the securing means N131, whereafter the spacer plates 89 and 81 can be shifted radially and, when free of the hammer head recess, even-,

tually slipped off the mill shaft if desired. Endwis e displacement of the interfitted parts within the recess 69 is then possible, which allows the hammer head 70 to be removed from the hammer shank.

It will be seen from the foregoing that under the present invention parts of a hammer for a hammer mill are easily separated, making removal of the hammer head a convenient matter, either for complete replacement or reversal. Thus, since the hammer is usually worn down more rapidly on the end that faces the direction of the applied impacting forces, it is advantageous to reverse the hammer after a time to present the fresh end for working. In any event, separation is effected without the need to disassemble or dismantle parts of the hammer mill, heretofore required, and this saves substantially on the cost of mill down time.

Spreading of the hammer arms on the shaft MS, due to any unbalanced moment, is substantially eliminated, because the various projecting and recessed parts of the shank elements are balanced. This also eliminates excessive stress on the shanks of the securing bolts, although the securing bolts act merely as retainers to assure proper alignment of the parts. In fact, loss of the bolt would not hinder operation of the mill in the present instance, because the hammer head would remain engaged with the hammer shank as long as the hammer is rotated.

As noted above, separation is a relatively easy task, since completion of the first step, that is, removal of the bolt, permits the spacer plate or plates to be swung free of the recess in the hammer head and then moved radially with respect to the main shaft to a removal or ineffective location, whereafter the shank sections are either moved endwise together (FIG. 2) or spread endwise apart (FIG. 7) to separate the interfitted shank and head parts, making possible removal of the hammer head. If difiiculty is encountered in removing the spacer plate because of material accumulated in the hammer head recess, a rod or the like can be used as above noted to clear the recess of debris.

It may finally be noted that the hammer head is recessed and symmetrically sloped surfaces or ledges are presented within the recess to interfit with complementally shaped surfaces on the shank part of the hammer. This encourages seating or self-centering since the head and shank parts, as will be noted from the drawings, are symmetrically distributed about the interfitting surfaces which themselves are symmetrical.

Hence, while preferred embodiments of the invention have been described and illustrated, it is to be understood that they are capable of variation and modification, and I therefore do not wish to be limited to the precise details set forth, but desire to avail myself of such changes and alterations as fall within the purview of the following claims.

I claim:

1. A hammer of the kind described for a hammer mill including a head formed with a recess and a shank having detachable interfitting parts, said shank being adapted to be secured to a hammer mill shaft to dependingly relate the hammer to the shaft, said hammer comprising separate spacer means normally disposed in an effective position to maintain the shank and head in inter-fitting engagement, said spacer means being slotted at one end to fit said shaft and by virtue of the slot being movable on said shaft out of the effective position to an ineffective position where the shank and hammer head are detachable one from another, and releasable means maintaining the spacer means disposed as aforesaid and adapted to be released to enable the spacer means to be moved to its ineffective position.

2. A hammer of the kind described for a hammer mill including a separable two-piece shank member, each piece identical, and a head member formed with a recess therein, said members having parts detachably interfitted within the recessed portion of the head, said shank pieces each having an opening adapted to embrace a hammer mill shaft incidental to hanging the hammer thereon, spacer means slotted at one end to embrace said shaft and normally depending therefrom with the opposite end thereof in an effective position within the recessed portion of the head member to maintain the interfit-ting parts in engagement, said spacer means being movable with respect -to said shaft to an ineffective position where at said shank pieces and head can be detached one from another, and releasable means securing the shank pieces together and maintaining the spacer means in its effective position and adapted when released to enable the spacer means to be moved to the ineffective position.

3. A hammer of the kind described for a hammer mill including a head member and a two-piece shank member, said members having detachable interfitting'parts, said shank member being adapted to be secured to a hammer mill shaft to dependingly relate the hammer to the shaft, said hammer comprising separate spacer means slotted at one end to embrace said shaft and normally disposed between the shank pieces in an effective position to maintain the shank and head in interfitting engagement, said spacer means by the slot formation therein being removable from the shaft to an ineffective position where the shank and hammer head are detachable one from another, and releasable means securely joining the shank pieces and the spacer means to hold the spacer means disposed as aforesaid and adapted to be released to enable the spacer means to be moved to its ineffective position.

4. A hammer of the kind described for a hammer mill including a head formed with a recess in part limited by overhanging projections, a pair of identically shaped shaped shank elements having projections detachably interfitting with said overhanging projections, said shank elements being adapted to be secured to a hammer mill shaft to dependingly relate the hammer to the shaft, said hammer comprising a substantially flat spacer plate normally interposed in an effective position between said shank elements to maintain the shank elements and head in interfitting engagement, said spacer plate having a slotted end adapted to fit said shaft and thereby being movable on said shaft out of the effective position to an ineffective position where the shank elements and hammer head are detachable one from another, and releasable means securely joining the shank elements and the spacer plate to hold the spacer plate disposed as aforesaid and adapted to be released to enable the spacer plate to be moved to its ineffective position.

' 5. A hammer of the kind described for a hammer mill including a two-piece shank member formed with a recess therein, each piece identical and arranged in back-to-back relationship with respect to one another, and a head having parts detachably interfitted with complemental parts on the shank pieces centrally located within the recessed portion of the head, said shank pieces each having an opening at one end adapted to embrace a hammer mill shaft incidental to hanging the hammer thereon, a pair of spacer plates slotted at one end to embrace said shaft and normally depending therefrom at the outer sides of said shank pieces with the opposite ends thereof in an effective position within said recess to urge the interfitting parts into engagement, said spacer plates being movable with respect to said shaft to an ineffective position whereat said shank pieces and head can be detached one from another, and releasable means securing the shank pieces together and maintaining the spacer plates in effective position and adapted when released to enable the spacer plates to be moved to the ineffective position.

6. A hammer of the kind described for a hammer mill including a head member formed with a recess and a two-piece shank member having detachable interfitting parts within said recess in the head member and displaceable endwise from one another within said recess, the pieces affording said shank member being of identical construction and being adapted to be secured to a hammer mill shaft to dependingly relates the hammer to the shaft, said hammer comprising at least one spacer plate normally disposed with the lower end thereof in an eifective position in the hammer head recess to prevent endwise displacement as aforesaid, said spacer plate having the upper end slotted to fit said shaft and said spacer plate thereby being movable on said shaft to remove said lower end thereof from the effective position to an ineffective position Where endwise displacement as aforesaid is possible, and releasable means for holding the spacer plate disposed as aforesaid and adapted to be released to enable the spacer plate to be moved to its inefiective position.

7. A hammer of the kind described for a hammer mill including a head member having a recess formed therein and a two-piece shank member having detachable interfitting pants engaged within the recess in the head memher, the pieces affording said shank member being adapted to be secured to a hammer mill shaft to dependingly relate the hammer to the shaft, said hammer comprising at least one spacer element having one end thereof nor 5 mally disposed in an effective position in said recess in the head to maintain the shank and head in tight interfitting engagement, said spacer means being slotted at one end to fit the shaft thereby being movable radially on the shaft out of the eifective position to enable the shank and hammer head to be detached one from another, and releasable means for holding the spacer element disposed as aforesaid and adapted to be released to enable the spacer element to be moved to its inefiective 10 position.

UNITED STATES PATENTS References Cited in the file of this patent 

3. A HAMMER OF THE KIND DESCRIBED FOR A HAMMER MILL INCLUDING A HEAD MEMBER AND A TWO-PIECE SHANK MEMBER, SAID MEMBERS HAVING DETACHABLE INTERFITTING PARTS, SAID SHANK MEMBER BEING ADAPTED TO BE SECURED TO A HAMMER MILL SHAFT TO DEPENDINGLY RELATE THE HAMMER THE SHAFT, SAID HAMMER COMPRISING SEPARATE SPACER MEANS SLOTTED AT ONE END TO EMBRACE SAID SHAFT AND NORMALLY DISPOSED BETWEEN THE SHANK PIECES IN AN EFFECTIVE POSITION TO MAINTAIN THE SHANK AND HEAD IN INTERFITTING ENGAGEMENT, SAID SPACER MEANS BY THE SLOT FORMATION THERE- 